Abstract: In an implantable medical device and a method and computer-readable medium for operating the medical device to detect a condition of a heart of a patient, activity level of a patient and acoustic energy in a patient are sensed, and acoustic signals are generated that are indicative of heart sounds of the patient over predetermined periods of a cardiac cycle during successive cardiac cycles. A signal corresponding to a first sound is extracted from the sensed acoustic signal of a cardiac cycle. A relation is calculated between a first signal corresponding to the first heart sound in a first activity range, and a second signal corresponding to the first heart sound in a second predetermined activity level range. The calculated relation is compared with at least one reference value to detect the condition or a change of the condition.

Abstract: A method for operating an implantable medical device to obtain substantially synchronized closure of the mitral and tricuspid valves based on sensed heart sounds includes sensing an acoustic energy; producing signals indicative of heart sounds of the heart of the patient over predetermined periods of a cardiac cycle during successive cardiac cycles; calculating a pulse width of such a signal; and iteratively controlling a delivery of the ventricular pacing pulses based on calculated pulse widths of successive heart sound signals to identify an RV interval or VV interval that causes a substantially synchronized closure of the mitral and tricuspid valve. A medical device for optimizing an RV interval or VV interval based on sensed heart sounds implements such a method and a computer readable medium encoded with instructions causes a computer to perform such a method.

Abstract: A method for operating an implantable medical device to control a stimulation therapy includes the steps of: sensing an acoustic energy; producing acoustic signals indicative of heart sounds of the heart of the patient over predetermined periods of a cardiac cycle during successive cardiac cycles; extracting a signal corresponding to a first heart sound (S1) from a measured acoustic signal; calculating an energy value corresponding to the extracted signal; storing the energy value corresponding to the first heart sound; and initiating an optimization procedure, the optimization procedure comprising the steps of: iteratively controlling a delivery of the pacing pulses based on successive energy values corresponding to successive first heart sound signals and determining an optimal PV interval or AV interval with respect to the energy values. A medical device and a computer readable medium to implement the method.

Abstract: In an implantable heart stimulator and a method for operation thereof, stimulation pulses are delivered to a heart. The amplitude of the delivered stimulation pulses can be selectively set. For setting the amplitude, threshold searches are performed at selected time intervals. Each threshold search determines a threshold value required for achieving capture. The amplitudes of the respective stimulation pulses are set to a value that exceeds the determined threshold value by a safety margin. The safety margin is selected as a function of the selected time intervals.

Abstract: In a medical device and a method for operating the medical device, it is first determined whether a patient, at whom a medical measurement is to be made, satisfied specified criteria that will ensure comparability of the measurement results obtained from the patient. Only when the specified criteria had been satisfied is an electrical bio-impedance signal obtained from the patient. The cardiac component of the electrical bio-impedance signal is extracted, and is analyzed to identify a change in a medical condition of the patient.

Abstract: In a method, device and compute-readable medium for evaluating the prevalence of different postures of a patient, signals are sensed that indicate the posture of the patient during a monitoring period having a predetermined length, specific body postures of the patient are determined during this monitoring period from the sensed signals, the amount of time the patient spends in each of the specific postures is measured, information regarding each specific posture, and the associated amount of time spent in that posture, are stored, and the prevalence of the different postures of the patient is evaluated by classifying the stored information with respect to specific postures and the amount of time in each posture position.

Abstract: A peristaltic pump for conveying a fluid comprises a flexible tube having an outer surface and a lumen for carrying the fluid such as a therapeutic agent. The tube has a length defined by opposed ends of the tube, the outer surface of the body carrying a plurality of longitudinally spaced-apart electroactive polymer actuators. The plurality of actuators are adapted to be responsive to electrical signals for energizing the actuators sequentially along the length of the tube to move a lumen pinch-off along the length of the tube to thereby convey the fluid from one end of the tube to the other end by means of a peristaltic pumping action. The peristaltic pump may be incorporated into a medical lead, such as an endocardial pacing lead, carrying at least one electrode.

Abstract: In an implantable heart-monitoring device and system, and a heart-monitoring method, a control circuit is connected to one or more sensors, a first of which is positionable in the coronary sinus region of a heart and senses at least one blood constituent, and at least one other of the sensors supplying a signal to the control circuit indicative of the activity of the heart. In response to signals from the first sensor and with information about the activity of the heart from the other sensor, the control circuit determines a first value of the blood constituent during a first portion of a heart cycle, and determines a second value of the blood constituent during a second portion of the heart cycle.

Abstract: In a cardiac assist device and method, a microphone is placed in contact with the epicardium of the heart of a patient, and heart and lung sounds are simultaneously detected at the placement location of the microphone. The heart and lung sounds are automatically analyzed to set an appropriate cardiac therapy for the patient.

Abstract: A heart monitoring device has a control circuit that derives an impedance value indicative of the impedance between different electrode surfaces. The control circuit determines and monitors a negative rate of change of the impedance value and determines whether the negative rate of change, or its absolute value, increases or decreases over a number of heart cycles. Alternatively or additionally, the control circuit may determine and monitor a relationship between a positive rate of change and a negative rate of change of the impedance value. The device can, in particular, be used to detect and treat a diastolic dysfunction of a heart.

Abstract: In a method and apparatus for measuring the ejection fraction in a mammalian heart, the opening and closing of a heart valve is sensed with an implanted sensor, and a pre-ejection period is measured as a function of the sensed opening and closing of the heart valve. The ventricular ejection time also is measured, and the ejection fraction is determined as a function of the measured pre-ejection period and the ejection time.

Abstract: An implantable bi-ventricular heart stimulating device and system, suitable for treating congestive heart failure, have a control circuit with first and second pacing circuits and first and second sensing circuits. The device operates with time cycles corresponding to normal heart cycles. The control circuit determines: (a) whether a signal typical of an evoked response to a pacing pulse delivered by the first pacing circuit is sensed within a first time interval and (b) whether a signal typical for an R-wave transferred from the second ventricle, or from some other part of the heart, to the first ventricle is detected within a first time window. The operation of the device depends on whether the conditions (a) and (b) are fulfilled.

Abstract: An implantable cardiac stimulation device has an atrial detector that detects atrial events of a patient's heart, and a memory in which sequences of IEGM signals are stored, having a predetermined length, and an analyzing unit that analyzes the sequences to determine if the stored sequences contain atrial events having a lower amplitude than the current sensitivity setting of the atrial detector. A control unit is connected to the atrial detector to adjust the sensitivity setting thereof to a threshold that is determined based on the aforementioned analysis of the IEGM signals.

Abstract: In an implantable heart stimulating device, system and method, a control circuit has first and second circuits for sensing and pacing. The first circuit can be connected to a first electrode member suited to be positioned in or at a first ventricle of the heart. The second circuit can be connected to a second electrode member suited to be positioned in or at a second ventricle of the heart. The control circuit is able to detect whether signals sensed by the second circuit are likely to be far field signals. The control circuit performs this detection by at least determining whether, during a predetermined time (length, more signals are sensed by the second circuit than by the first circuit.

Abstract: An implantable bi-ventricular heart stimulating device and system operate, within a time cycle, to deliver pacing pulses with both a first and a second pacing circuit with a first time delay between these pacing pulses. The device employs a criterion with which a signal typical for a premature ventricular contraction is detected. The device also operates with a second time delay and/or with a third time delay, and, if a predefined pacing rule is fulfilled, to deliver a pacing pulse with the second time delay or said third time delay. The risk for arrhythmia in connection with a PVC is reduced.

Abstract: A heart stimulator for electric stimulation of a patient's heart has an impedance measuring unit that measures the impedance between at least two measurement electrodes implanted in a patient such that volume changes of at least one of the chambers of the left heart result in changes in the measured impedance. An analyzer analyzes the measured impedance for the control of the stimulation of the heart. A calculation unit calculates an average impedance morphology curve during a time interval of several cardiac cycles. The analyzer analyzes the average impedance morphology curve for use for the control of the stimulation to optimize the patient hemodynamics.

Abstract: A heart monitoring device has a control circuit, the control circuit being adapted to be electrically connected to electrode surfaces arranged at two different positions of the heart. The control circuit derives an impedance value indicative of the impedance between the electrode surfaces. Furthermore, the control circuit is arranged to determine and monitor a relationship between a positive rate of change and a negative rate of change of the impedance value. The device can, in particular, be used to detect and treat a systolic dysfunction of a heart.

Abstract: A congestive heart failure monitor has an impedance measuring unit that measures the impedance between at least two electrodes implanted in a patient, to use a detected change of the measured impedance as an indication of a change in the left atrium volume. Any analyzing unit analyzes the measured impedance and detects insipient congestive heart failure dependent on a quotient of a maximum value of the measured impedance and a minimum value of the measured impedance during a cardiac cycle.

Abstract: A multi-chamber pacing system has a pulse generator for successively delivering pacing pulses to chambers of a patient's heart. Evoked response detectors having blanking intervals following the delivery of pacing pulses include sensing elements for sensing IEGM-signals from each of the heart chambers and an integrating unit that integrates the IEGM-signal within evoked response detection time windows after delivery of pacing pulses for detecting evoked response. The evoked response detection time window for a heart chamber contain at least one blanking interval resulting from delivery of a pacing pulse to another chamber and each of the sensed IEGM signals having a generally known morphology. An integral reconstructing unit reconstructs the time integral of the IEGM signal from one of the heart chambers in the blanking interval following delivery of a pacing pulse to another heart chamber.

Abstract: An implantable bi-ventricular heart stimulating device (10) has a control circuit with first and second sensing circuits for respectively sensing in the two ventricles and first and second stimulation circuits for respectively stimulating the two ventricles. The control circuit determines whether a signal, sensed by said second sensing circuit, occurs essentially simultaneously with a signal sensed by the first sensing circuit. Furthermore, the control circuit determines whether a further signal is sensed by said second sensing circuit within a predetermined time interval which follows after the signal sensed by the second sensing circuit but within the same time cycle as that signal. If this occurs, the control circuit determines whether the sensed signals represent actual cardiac events, or are likely the result of far field detection.